Woodburning stoves, either free standing or inserted into fireplace openings have, with the advent of high fossil fuel prices, become very popular. With the popularity has come more efficient wood stove designs. For example, U.S. Pat. Nos. 4,166,444; 4,214,569; 4,271,815; and 4,213,443 disclose heat exchange tubes through a stove, a heat exchange jacket around a firebox, and a flue baffle. Baffles above the fire box of a furnace are also shown in U.S. Pat. No. 4,319,557. All of these modifications shown by the prior art greatly enhance the amount of heat that can be extracted from a given quantity of fire wood.